ABB ACS560 Firmware Manual page 35

Two external control locations, EXT1 and EXT2, are available. The user can select
the sources of the start and stop commands separately for each location by setting
parameters 20.01...20.10. Selection between EXT1 and EXT2 is done via any binary
source such as a digital input or fieldbus control word (parameter
selection). The source of reference is selectable for each operating mode separately.
Communication fail functionality
The communication fail functionality ensures continuous process without
interruptions. If there is a communication loss, the drive automatically changes the
control location from EXT1 to EXT2. This enables process to be controlled, for
example, with the drive PID controller. When the original control location recovers,
the drive automatically switches control back to the communication network (EXT1).
EXT1/EXT2 selection for speed control
Input 1
Input 2
Input 3
Input 1
Input 2
Input 3
Input 1
Input 2
Input 3
Input 1
Input 2
Input 3
Ext1 speed ref1
22.11
Ext1 speed ref2
22.12
Ext2 speed ref1
22.18
Ext2 speed ref2
22.19
Function
Ext1 speed ref1
EXT1
or a math.
function of Ext1
speed ref1 and
Ext1 speed ref2
22.13
Function
Ext2 speed ref1
or a math.
function of Ext2
speed ref1 and
EXT2
Ext2 speed ref2
22.20
Program features 35
19.11 Ext1/Ext2
Select
Default =
EXT1
19.11
Ext1/Ext2 selection